1. Field of the Invention
The present invention relates to uplink transmission power in the field of wireless communications, and in particular, to a method and an apparatus for uplink transmission power control (TPC) of multi-link connections.
2. Description of the Prior Art
The Long Term Evolution (LTE)/LTE-A (LTE-Advanced) project is the biggest new technology R&D project launched by the 3rd Generation Partnership Project (3GPP) in recent years, and this technology, with the orthogonal frequency division multiplexing/frequency division multiple access (OFDM/FDMA) as a core, is regarded as a “quasi-4G” technology. The LTE/LTE-A will be the leading wide-area broadband mobile communications system, and in the future, all 2G, 3G, and 3.5G technologies will be advanced to the LTE/LTE-A stage.
As low-power nodes improve the capacity and solve the problem of blind spot coverage, the deployment and increase of small cells draw great attention in the LTE/LTE-A, and related achievement has been expressed in 3GPP R12. If a user equipment (UE) establishes multiple link connections, for example, establishes a first connection with a macro cell and establishes a second connection with a pico cell (the pico cell is typical small cell), the UE can avoid frequent handovers among densely deployed pico cells through the first connection with the macro cell, and at the same time, can obtain a throughput gain through the second connection with the pico cell. However, how to implement uplink TPC while supporting multi-link connections, especially in a co-channel case, becomes a problem that must be solved. If this problem cannot be solved, further development and application of the multi-link connection technology will be affected.